In the packing of various liquid foods, for example juice, milk or the like, in consumer packages of the type which comprises a container body of, for example, plastic or combinations of plastic and paper and also a closure device, it is normal that the packaging container body and the closure device are manufactured separately, whereafter they are transported individually to a filling machine by means of which the packaging containers are filled and provided with the closure device. During the transport of the packaging containers from the manufacturer to the juice or milk producer (i.e. the packer) dirt or foreign matter is prevented from entering into the packaging containers either with the aid of specifically designed protective sheets, or in that the packaging container bodies are packed in large crates, and protected with shrink film or by other means. Soiling of the closure devices is prevented in that the closure devices are packed in plastic bags or in crates. When the packaging containers are to be filled and provided with the closure devices at the packer, it becomes, therefore, necessary to free the packaging container bodies and closure devices from their protective envelopes and feed them individually into a filling machine which is also supplied with the product which is to be filled into the packaging containers. The separate handling of the packaging container bodies and the closure devices or screw caps, together with handling of the outer transport packaging is often seen as inconvenient by the packer, and requires extra personnel, for which reason there is a general need in the art to simplify this handling and, in a convenient manner, obviate the risk of dirt contamination of the packaging containers and the closure devices during transport from the producer to the packer.
In the aseptic packing of, for example, drinks not only are cleaning and inspection of the packaging container bodies necessary, but also sterilisation of both the packaging container bodies and the closure devices before the contents are packed into the packages. Such handling requires extra personnel and work at the packer's, for which reason an alternative solution is to carry out a cleaning and inspection of the packaging containers and the closure devices in an earlier stage, as well as to ensure that the transport packaging is such that the standard of hygiene is not jeopardised during transport from the producer to the packer. However, the risk of dirt contamination during transport and handling cannot be entirely precluded using present methods, which necessitates an additional inspection and possible cleaning of the individual packaging container bodies and closure devices prior to the final sterilisation, which is undertaken immediately before the filling operation proper.
In particular in aseptic packing, it is of crucial importance that the closure device and its surfaces and those of the packaging container which are to cooperate with one another in order to create an aseptically tight, i.e. bacteria-tight packaging container be also protected from mechanical damage during handling and transport. Even small chips and scratches in these surfaces jeopardise the bacteria-tightness of the finished packaging container to such an extent that the maintenance of the pristine sterile conditions cannot be guaranteed. These demands of preventing purely mechanical damage place further demands on, and further complicate, the outer transport packaging, for which reason there is an urgent need also from this viewpoint to simplify the handling methodology such that the risk of untightness is reduced. The fact that each closure device/packaging container body are not absolutely identical may also entail a risk of micro-leakage after closure and sealing of the packaging container, and so some form of tightness control is normal in order to ensure that the necessary manufacturing tolerances do not, under unfortunate circumstances, result in a given combination of packaging container body/closure device that fails to provide complete tightness.